U.S. Pat. No. 4,346,196, granted Aug. 24, 1982 to Hoh et al., discloses 80/20-20/80 blends of an ionomer dipolymer with an ionomer terpolymer and the use of such blends in the production of heat-sealable films for use in flexible film packages to create both tearable and peelable seals in the flexible film package. Hoh et al. does not use an ethylene/.alpha.-olefin copolymer in the blend, and while Hoh et al. does disclose that suitable heat seals can be achieved over a broad temperature range, the strength of such seals is temperature dependent.
U.S. Pat. No. 4,279,344, granted July 21, 1981 to Holloway, discloses blends of an ionomer with a propylene/.alpha.-olefin copolymer and the use of such blends in the preparation of heat sealable films for use in laminated packaging structures to create peelable seals. Holloway, however, discloses blends that are high in the propylene/.alpha.-olefin copolymer (i.e. at least 65 weight percent) and low in the ionomer (i.e. at most 35 weight percent). In addition, Holloway declares his objective to be the creation of peelable seals of moderate strength that can tolerate temperatures necessary for retort sterilization (i.e. about 250.degree. F.). Such is not the objective of the peelable seals of the present invention, which, in fact, are not retortable. In addition, Holloway's blend requires a seal temperature of about 450.degree. F., which is much higher than what would be used with the blends of the present invention.
U.S. Pat. No. 3,819,792, granted June 25, 1974 to Ono et al., discloses blends C-2 or C-3 olefin homopolymer or copolymer with ethylene/methacrylic acid ionomer that can be high in ionomer, but only up to a maximum of 70 weight percent. Ono discloses such blends as being useful in the production of double wall tubing. No mention is made of possible use in heat sealable film.